void startup()           //数据初始化；
{
	position_x =hight/2;
	position_y =width/2;
	canvas[position_x][position_y]=1; 	
	int k;
	for(k=0;k<EnemyNum;k++){
		enemy_x[k]=rand() %3;            //初始化敌机位置；
		enemy_y[k]=rand() %width;
		canvas[enemy_x[k]][enemy_y[k]]=3; 	
		
	}
	score=0; 
	life=6;
	level=0; 
	HideCursor();                    //禁止光标闪烁；***********************************
}
